Ural lake pointed out the existence of “oasis” ice age
Norwegian scientists have analyzed sediments of lake Bolshoye Shchuchye, the deepest of the Ural lakes and found that in the polar Urals during the last ice age there were “oasis”: the area is not constrained by ice. The new data explain why people lived here in an era when much more southern lands of modern Russia was covered by a kilometer-long glacier.
The scientists collected samples of drilling the sedimentary rocks of lake Bolshoye Shchuchye, located North of the Arctic circle, in the Arctic part of the Urals. They made samples of securely dated by the radiocarbon method and contain chronologically continuous layers over the past 24 000 years (the total thickness of the studied layer — 24 meters). This means that they relate to the period since the last glacial maximum — the time when the advancing glaciers to the South was the highest. Then on the East European plain of the glacier is about a kilometer thickness moved to the South of modern Moscow region.
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As the analysis has shown, even in the coldest period, to 24.9 18.7 thousand years ago, in the sediments of the lake was seasonal layering. This is typical for open water who have no permanent ice cover. That is, if a Large village and we froze in winter, in summer thawed. Thus, this whole area was free from the glacier, indicating relatively warm (by the standards of the glacial maximum) climate.
At the same time, in the coastal areas of the lake traces, periodic occurrence of masses of ice are present. The authors believe that it was a local small glaciers that were adjacent to the pond mountains. Only about 14.35 thousand years ago, the situation is changing and the ice is obviously moving away from the area surrounding the lake. Just at this time there and a General retreat of the glacier.
Interestingly, over the entire period, despite some periods of the return of the cold climate (early Dryas), no sign of the return of the ice no — apparently, they were unable to come to the lake with the nearby mountains for periods of relatively short cold snaps.News
The new data are important because this is the first set of continuous historical information on the climate of the region. All the Asian part of the Russian Arctic, from the point of view of climate science, is insufficiently studied region, because of bottom lake sediments are frequently used as an important source, there are in many places interrupted (during movements of the masses of ice, the soles of glaciers strongly moved and mixed sediment).
The work indicates that in that area there was a kind of “oasis”. This may explain the archeological findings of the people in the Arctic even during the onset of the glaciers. Apparently, there was a separate “pockets”, free from solid ice, although the causes of their formation are still not entirely clear.